Press for progressive compression of liquid-bearing absorbent article

ABSTRACT

A press for compressing a liquid-bearing absorbent article to transfer a portion of the liquid materials to a contiguous article has two concentric pressure feet. One is an outer foot member that bears against the liquid-bearing article along the periphery of the pressure area, and the other is an inner, deformable and contoured foot member that applies pressure to the liquid-bearing article progressively along the pressure area. A photometer can be combined with the press to measure constituents or other properties of the liquid materials being transferred.

United States Patent 91 Sodickson et al.

[451 Oct. 29, 1974 PRESS FOR PROGRESSIVE COMPRESSION OF LIQUID-BEARINGABSORBENT ARTICLE [75] Inventors: Lester A. Sodickson, Newton, Mass;

Franklin Lim, Richmond, Va.

[73] Assignee: Damon Corporation, Needham Heights, Mass.

22 Filed: Apr.ll, 1972 21 Appl. No.: 243,028

[52] US. Cl 23/253 R, 100/211, 23/259 [51] Int. Cl. B30b 9/04, G01n31/00 [58] Field of Search 23/253 R, 259, 252 R, 292; 100/211;162/396-401; 210/204, 224;

[5 6] References Cited UNITED STATES PATENTS 1,949,472 3/1934 Hopkinson162/401 2,714,349 8/1955 Johnston 162/399 3,255,476 6/1966 Dawson3,377,947 4/1968 Rickard 100/211 Primary Examiner-Morris O. WolkAssistant Examiner-T. W. Hagan Attorney, Agent, or Firm-Kenway & .lenney[57] ABSTRACT A press for compressing a liquid-bearing absorbent articleto transfer a portion of the liquid materials to a contiguous articlehas two concentric pressure feet. One is an outer foot member that bearsagainst the liquid-bearing article along the periphery of the pressurearea, and the other is an inner, deformable and contoured foot memberthat applies pressure to the liquid-bearing article progressively alongthe pressure area. A photometer can be combined with the press tomeasure constituents or other properties of the liquid materials beingtransferred.

17 Claims, 7 Drawing Figures PRESS FOR PROGRESSIVE COMPRESSION OFLIQUID-BEARING ABSORBENT ARTICLE BACKGROUND This invention relates to apress for compressing an absorbent article to squeeze liquid materialsfrom it. More particularly, the invention provides a press fortransferring liquid and dissolved materials from one absorbent articleto another layered with it. A particular feature of the invention is theprovision of such a press that transfers the liquid materials with onlyminimal lateral spreading. This is desired to avoid loss of liquidmaterials in the first article and thereby to transfer the utmost volumeof materials to the second article, and to concentrate the transferredmaterials in a confined region of the second article.

A press embodying the invention is particularly useful in connectionwith the analysis of a biological liquid sample to identify theconcentration of one or more constituents. According to one techniquefor such an analysis as disclosed for example in U.S. Pat. Nos.3,036,893; 3,216,804; 3,219,416; 3,260,413; 3,261,668; 3,331,665;3,368,872; and 3,502,438; the sample is deposited on a first absorbentpad and then transferred to a second absorbent pad where, with theaddition of chemical reagents, a reaction product is developed in anamount dependent on the concentration of a constituent in the originalsample. The abovenoted Natelson U.S. Pat. No. 3,261,668 discloses anelementary flat-bed type of press for sqeezing two layered pads togetherto enhance the transfer of liquid materials between them. However, thisprior art press generally transfers only a relatively small portion ofthe liquid materials in one pad to the other pad; due, at least in part,to the fact that the press spreads the liquid. The press of the NatelsonU.S. Pat. No. 3,331,665 operates with disks of the pad material and doesnot restrict spreading of liquid within the disks.

Also in the prior art are teachings regarding metalworking punchpresses, such as is disclosed in Henricson U.S. Pat. No. 1,723,935,which strip the work piece from the punch after the punching operation.U.S. Pat. Nos. 2,160,676; 2,168,377; 2,265,331; 2,268,787; and 2,350,436disclose further punch presses of this type.

SUMMARY OF THE INVENTION A press embodying the invention and for thetransfer of portions of a biological liquid sample and of selecteddissolved constituents between two absorbent pads as noted above has twoconcentric pressure feet. An outer pressure foot engages the pads alongan outer annular pressure surface, and generally with a resilient force.The inner pressure foot engages the pads initially along an annular areacontiguously within the pressure surface of the outer foot, and thenprogressively inward along the entire pressure surface of the innerfoot.

This pressing action that progresses inward from an outer peripheralring to the center of the pressure area constrains liquid materialsabsorbed in the pads from spreading laterally outward. Instead, it urgesthe liquid materials in the initial liquid-bearing pad laterally inwardto the center of the pressure area, as well as transversely into theother pad layered with it. Thus, the invention provides a press thattransfers an utmost volume of liquid material from a selected localizedarea of one pad to the other, without significant loss due to lat- LIIerally outward spreading of the fluid; and delivers the liquid materialsto a confined area of the second pad. It should be noted that both padscan be cards, sheets or strips large enough to embrace many suchconfined areas.

Considered more broadly, the invention provides a press that subjectsthe article being pressed to a pressing force that is resilient and thathas a tailored distribution such that the pressing force progressesacross the pressure area.

In accordance with a further feature of the invention, a press of theabove character compresses absorbent pads along an annular path andadmits a pipette nozzle or other fluid conduit to deposit a liquid ontothe compressed pads inside the annular area of compression. Afterremoval of the nozzle, the presswhile maintaining the annularliquid-constricting compression-compresses the pads throughout the areawithin the annular area of initial compression. 1

Further, a press according to the invention can be combined with aphotometer in a manner that enables the photometer to monitor at least asurface of the pads being compressed. A novel fluoromete'r is apreferred form of photometer for this arrangement.

The invention comprises the features of construction,

combinations of elements, and arrangement of parts exemplified in theconstructions hereinafter set forth, and the scope of the invention isindicated in the claims.

BRIEF DESCRIPTION OF DRAWINGS For a fuller understanding of the natureand objects of the invention, reference should be made to the followingdetailed description and the accompanying drawings, in which:

FIG. 1 is a perspective view, partly broken away, of a press embodyingthe invention and for the progressive compression of a liquid-bearingabsorbent article to transfer a portion of the liquid and of materialsdissolved in the liquid to a further absorbent article;

FIG. 2 is a fragmentary elevation view, partly broken away, showingdetails of the press of FIG. 1;

FIG. 3 is a view similar to FIG. 2 showing the press of FIG. 1 with thepressure feet in compressive engagement with the article being pressed;

FIG. 4 is a perspective view, partly broken away, of an accessory devicefor use with the press of FIG. 1;

FIG. 5 is a view similar to FIG. 2 showing a modified construction forthe press of FIG. 1;

FIG. 6 is a fragmentary side elevation view, partly broken away, of afurther embodiment of the invention incorporating a press and aphotometric instrument for examining the article being pressed; and

FIG. 7 is a fragmentary view of the press structure of FIG. 6 in thefully compressed condition.

DESCRIPTION OF ILLUSTRATED EMBODIMENT FIGS. 1 and 2 show a press 10 forsqueezing a sample 12 of biological liquid and dissolved materials froma localized region 13 of an absorbent collection pad 14 to a selectedlocalized site on an absorbent reaction pad 16. The sample is typicallyblood collected by blotting it into the collection pad 14 directly froma dermal puncture or with the aid of a transfer pipette or dropper. Aportion of the sample is to be transferred to the reaction pad 16 fortreatment there with one or more chemical reagents that produce, withthe transferred sample constituents, a reaction product that is ameasure the relative amount of a selected constituent in the originalblood sample. Thus, the collection pad 14, which generally is separatefrom the reaction pad 16 during the collection of the sample, is shownlayered above the reaction pad for the sample transfer operation whichthe press carries out. A microporous sheet filter 18 is interposedbetween the two pads to block large molecules in the sample, e.g., bloodproteins and hemoglobin, from being transferred to the reaction pad.After the transfer of sample to the reaction pad, the collection pad andfilter typically are stripped from it and the reaction pad thensubjected alone to the further constituent-analyzing processing.

With further reference to FIGS. 1 and 2, the press 10 has a base 20forming a platen 22 affixed to an upstanding post 24 that carries ashaft support 26 spaced opposite the platen. The support slidably mountsa press shaft 28 for reciprocation relative to the platen as indicatedwith arrow 30. A conventional mechanism, not shown, operated eithermanually as with a lever arm or automatically by means of a motor drive,moves the shaft 28 selectively toward and away from the platen as theoperator selects. The platen 22 can carry a pedestal 32 centered belowthe shaft 28 and on which the pads being pressed are placed, asindicated. At its lower end the shaft 28 threadably receives a threadedshank 34 of lesser diameter and which extends axially of the shaft. Adisk 35 is threadably mounted on the shank to provide a shoulder 36facing toward the platen 22.

The press shaft 28 carries two concentric foot members 38 and 40 on thelower end of the shank 34 for compressing work on the pedestal 32. Theinner foot member 38 is a core or pluglike short rod of elastomericmaterial affixed as by adhesive or mechanical attachment on the end ofthe shank as an axial extension thereof. The inner foot member,illustrated as having a circular cross section and cylindrical sidesurface, has on the bottom end a concavely domed pressure surface 42that flattens, as shown in FIG. 3, upon axial compression of the footmember between the shaft and pedestal.

The outer foot member 40 is a collar of metal or like rigid materialcoaxially fitted on the end of the shank 34 over the inner foot member38. The collar is slidable relative to the shank; a pin 44 is pressfitted into the collar wall and seated in a slot 46 extending in theshank along the shaft axis to retain the collar on the shaft. A coilspring 48 is compressively seated between the top of the collar and thedisk shoulder 36, encircling the shank 34, to urge the collar-like footmember forward along the shank toward the pedestal 32 for a distancelimited by the axial length of the slot 46, as in FIG. 2.

the outer foot member 40 has an annular flat pressure surface 50contiguously outside and encircling the domed pressure surface 42 of theinner foot member 38. The illustrated foot member 40 has a taperedthickness at its pressure end so that the radial width of the annularpressure surface 50 is narrow, which enhances the application of a largecompressive pressure to the layered pads 14 and 16.

The outer foot member 40 has an inner surface 52 that is cylindricalalong the length of the telescopic extension of that member over theshank 34, and at the extreme end of the member 40 adjacent its pressuresurface 50, and along the end of the inner foot member connected to theshank for approximately the distance by which inner foot memberdecrease-sin length upon being fully pressed against the pads or otherwork on the pedestal.

The portion 52a of the surface 52 along the rest of the outer footmember is recessed outwardly. This recess forms a generally toroidalrelief space 54 into which the inner foot member can bulge,substantially without restriction, when compressed as shown in FIG. 3.The surface portion 52a has a rounded contour and forms a smoothtransition with the cylindrical sections of surface 52; for the purposeof allowing the two foot members to move, and the inner member to bulge,with minimal interference between them.

With the foregoing construction, when the shaft 28 moves down, towardthe pads on the pedestal 32, the pressure surface 50 and the outermostedge of the domed pressure surface 42 engage the pads first. Thesesurfaces compress the pads only along an annular area.

Continued descent of the shaft 28 presses the outer member down furtherwith a resilient force as the spring 48 is increasingly compressed. Itis considered preferable that the slot 46 extend along the shank forsuch a length that the pin 44 does not bottom against the slot upperend, which would then result in the outer member 40 being pressed withrigid force. Simultaneously, the inner foot member 38 is compressedaxially. This causes it to bulge outwardly, into the recess 54, andgradually flattens the normally domed pressure surface 42. Thus, thecompressive force on the pads progresses inward from the annular area ofinitial compression until the entire area under the surfaces 50 and 42is compressed.

This progressive compression of the pads 14 and 16 in accordance withthe invention constrains the liquid sample 12 from spreading laterallyoutward. Instead, the sample is squeezed essentially straight downagainst the filter 18. This action transfers theoretically as much asone-half of the small-molecule portion of the sample to the portion ofpad 16 lying directly under the pressure surface 42 of the inner footmember 38; in practice, typically 20 percent is transferred.

FIG. 3 shows the condition of the foot members of the press 10 when theshaft is at its lowermost position, i.e., at the position of fullcompression.

The shank 34 is threadably affixed to the shaft 28 to allow the shank tobe threaded further into or out of the shaft and thereby adjust thepressure with which the foot member 38 engages pads on the press platen22, and/or to allow operation with pads of different thicknesses. Thisadjustment of the shank 34 relative to the shaft 28 does not alter thecompression of spring 48, which is done independently by threading thedisk along the shank.

The provision of the relief space 54 between the two foot members 38 and40 allows the inner foot member 38 to compressively deform in the mannershown and thereby enables the normally domed pressure surface 42 toflatten progressively. In the absence of such a re lief space 54, thetwo foot members seize upon each other and the desired compression ofthe pads 14 and 16 is generally not fully attained.

It is considered preferable to form the relief space 54 with a geometrycorresponding to the deformation of the inner foot member 38 when fullycompressed, as

shown in FIG. 3. Accordingly, the cross section of the relief space asshown in FIG. 2 is that of a shallow concavity. However, the reliefspace 54 can be provided with other shapes and can in fact be madelarger than the laterally outward bulging of the inner foot member whencompressed. Moreover, the relief space 54 can, as shown in FIG. 5, beprovided by recessing the outer diameter of the inner foot member ratherthan by recessing the inner surface of the outer foot member. Thus, FIG.5, which shows elements corresponding to those in FIGS. 1 through 3 withthe same reference numerals with an additional prime, has an outer footmember 40' with an inner surface 52 that is of right cylindrical shapethroughout the length of the outer foot member. Further, the inner footmember 38' has, in addition to the normally domed pressure surface 42,sidewalls forming an hourglass shape to provide the desired relief space54' between the two foot members. It will now be apparent that furtherarrangements can be employed, including one in which both the outersurface of the inner member 38 and the inner surface of the outer member40 are recessed to provide the relief space between them.

As further shown in FIGS. 1 through 3, the foot members 38 and 40illustrated carry a barrier sheet 56 on their pressure surfaces andwhich is interposed between these pressure surfaces and the uppermostsurface of the layered pads on the pedestal 32. The sheet 56 preventsthe pressure surfaces from being contaminated by the sample 12 and otherfluids or materials, e.g., chemical reagents, present with thecollection pads 14 and/or 16. A fresh barrier sheet 56 is provided foreach set of layered collection pads which the press processes; i.e., thesheet is discarded after a single use and replaced with a fresh one.This maintains the pressure surfaces free of contamination withoutrequiring cleansing or a more-costly disposable element.

FIG. 4 shows a tool 60 for use in affixing the barrier sheet 56 to thefoot members of the press 10. The tool has a rigid base 62 that carriesan upstanding collar 63 of elastomeric material, and a core 64 withinthe collar bore. The core is of a harder material than the collar 63,polytetrafluoroethylene such as is marketed under the trade nameTeflon," or metal can be used for the core. Further, the core has arounded upper surface conforming generally to the normally domed shapeof the inner pressure surface 42, whereas the upper surface of thecollar 63 conforms to the outer annular pressure surface 50, although itmay be wider than the latter surface.

In use, the fresh barrier sheet 56 is placed on the tool 60 as indicatedand the tool seated on the press pedestal 32. The press shaft 28 is thenlowered to compressively engage the pressure surfaces 50 and 42 with thetool collar 63 and core 64, respectively, with the barrier sheetinterposed between. This compression of the barrier sheet 56 against thepressure surfaces conforms it to them as shown in FIG. 2, and causes thebarrier sheet to self-adhere to the pressure surfaces, or to other outersurfaces of the foot member 40. A preferred material for the barriersheet is a thin film of paraffin, as is marketed under the nameParafilm.

To illustrate the construction of a press in accordance with theinvention, a press as shown in FIGS. 1 and 2 has an inner foot member 38of synthetic rubberlike elastomeric material as sold under the nameTygon having a normal, i.e., uncompressed, length of 0.50

inch, an outer diameter of 0.375 inch, and a dome recess ofapproximately 0.50 inch maximum depth. The relief space 54 extends foran axial length of 0.25 inch and has a maximum depth of approximately0.01 inch.

FIG. 6 shows another embodiment of the invention in which a pipettenozzle can introduce a reagent to layered pads 72, 74 being compressedwith a collarlike outer foot member 76 of a press 77, prior to beingcompressed with an inner foot member 78. Further, a photometer,illustrated as a fluorometer 80, is housed with the FIG. 6 press 77 tomeasure the reaction product produced in the reaction pad 74 while thatpad is in the press.

More particularly, the press 77, generally similar to the press 10 ofFIGS. 1 through 3, has a shaft shank 84 movable back and forth relativeto a platen 86 as indicated by arrow 88. The inner foot member 78,illustrated as similar to the inner foot member 38 of FIG. 5, has arecessed pressure surface 82 and an hour-glass sidewall 83 having acylindrical inner end section adja cent the shank, a cylindrical outerend section adjacent the pressure surface 82, and a thinned medial orwaist section between the end sections and forming between the two footmembers a recess of semi-lenticular crosssection. The foot member 78 isslidable within the bore of the outer member 76 with the sidewall endsections thereof in slidable engagement with the outer member bore andat least the outer end section forming a liquidtight seal with the outermember 76. As in the FIG. 1 press 10, the outer foot member 76 of FIG. 6is affixed to shank 84 by means of a pin seated in an axial slot 92 inthe shank 84, and a compression spring 94 urges the outer foot memberslidably forward relative to the shank in the direction toward thepedestal 86. The foot member 76 has'an inner surface 96 similar to thatdescribed above with reference to FIG. 5, although a relieved innersurface such as is shown in FIG. 2 can be used instead.

As also illustrated, the inner foot member 78 has a locking tab on theinner end seated in a mating slot in the press shank 84 to secure thefoot memberto the shank. Further, the shank and outer foot member 76 arearranged such that the press has a normal configuration similar to thatshown in FIG. 6, in which the compression spring 94 urges the outer footmember forward on the shank sufficiently to retract the inner footmember into the outer foot member to form a space 98 within the outerfoot member for admitting the pipette nozzle 70.

In addition to this structure, outer foot member 76 is of sufficientaxial length to contain the inner foot member 78 and the shank end towhich it is secured when the foot member is retracted into the member 76to form the space 98. Further, the outer foot member 76 has a passage100 through the sidewall 102 thereof and spaced closely above theannular pressure surface 104. As FIG. 6 shows, this passage 100 admitsthe pipette nozzle 70, or another fluid conduit, for the injection of afluid such as a diluent or reagent into the space 98 for deposition onthe collection pad 72.

As FIG. 6 further illustrates, in a typical use of the press 77, theshaft is moved toward the platen to compress the pads 72, 74 slightlywith the outer foot member 76, but without moving the inner foot memberinto the space 98, and is held in that position. The pipette nozzle 70is then inserted through the passage 100 to enter the space 98 and thedesired liquid is ejected onto the pad 72. The compressive engagement ofthe annular pressure surface 104 of the outer foot member against thepads 72, 74 precludes significant spreading of this liquid laterallyoutward beyond that pressure surface 104.

After the pipette nozzle is withdrawn from the space 98, the press shaftis moved further toward the platen to press the outer member furtheragainst the pad 72 and to slide the inner foot member 78 through thespace 98 and compress it against the pad 72, as shown in FIG. 7. Thiscompression transfers liquid materials from the pad 72 to the pad 74through the intervening filter.

When the inner foot member is moved toward the platen beyond the openingof passage 100 through the surface 96 of the outer foot member, theouter end section thereof seals liquid from leaking out from within theouter foot member by way of the passage 100. The sealing engagement ofthe inner foot member to the bore surface 96 of the outer foot memberincreases as the shaft shank 84 increasingly compresses the inner footmember 78.

When the transfer operation is complete and the shaft shank is drawnaway from the platen, spring 94 retracts the shank relative to the outerfoot member, drawing the inner foot member to the retracted position ofFIG. 6 where the space 98 is present.

With further reference to FIG. 6, the press base 106 also forms ahousing for the fluorometer 80. The fluorometer illuminates the reactionpad 74 with radiation from a lamp 108 through the press platen 86, whichis an optical window transparent to the incident exciting radiation ofthe lamp 108 and to the fluorescence which this radiation produces inthe reaction product of interest in the reaction pad 74.

More particularly, the base 106 has a primary passage 110 and asecondary passage 112 therein; the passages are coplanar and are angledrelative to each other with their central axes converging at the pad 74.The lamp 108 is mounted in the primary passage 110 in optical alignmentthrough the optical window of the platen 86 with the section of thereaction pad under the inner foot member 78. A primary filter 114 ismounted in the primary passage interposed between the lamp 108 and theplaten 86 to block unwanted radiation from illuminating the reactionpad. Further, a reference detector 116 for producing an electricalsignal responsive to the intensity and modulation of the illuminationfrom the lamp 108 also is mounted in the primary passage.

Although not required, the illustrated fluorometer secondary passage 112is oriented along the angle at which incident radiation from lamp 108reflects from the reaction pad 74. Thus, the illustrated fluorometer 80has the secondary pas'sage 112 aligned at the angle at which incidentenergy from lamp 108 reflects from the pad 74 surface which iscontiguous with the optically transparent platen 86. This geometry ispreferred to provide equal-length optical paths, from lamp 108 to thedetector 118 in the secondary passage 112, for illumination impinging onall points of the reaction pad 74 which are within the fluorometer fieldof view. The equal-length optical paths, in turn, result in highmeasuring accuracy and precision.

The secondary passage 112 mounts a fluorescence detector 118 and, inoptical alignment between the detector 118 and the reaction pad 74,mounts a lens 120 which focuses the desired fluorescence onto thedetector 118 and mounts secondary filters 122 and 124 and 126. Thesesecondary filters together block reflected radiation from the lamp 108and block fluorescence and other radiation above and below pass band ofthe fluorescence to be measured.

Further, the secondary filters are selected to be nonfluorescing, atleast in the wavelength range of measurement, when excited withreflected illumination from the lamp 108 and with whatever fluorescenceis present. Dielectric and metal film filter constructions are preferredto provide the filters 122, 124 and 126 with the desired degree ofnon-fluorescence. This provision of non-fluorescing secondary filters inaccordance with the invention results in an increase in sensitivity andbackground rejection of the fluorometer as contrasted to a fluorometerof similar construction except having glass or other secondary filterswhich are subject to producing fluroescence within the frequency rangeof measurement.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained. Sincecertain changes may be made in the above constructions without departingfrom the scope of the invention, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention which, as amatter of language, might be said to fall therebetween.

Optimum results are realized with the press described above when bothpads on the press initially are dry except for the liquid sample on thecollection pad. Further, it is preferred that the liquid sampleinitially be restricted to only the area below the inner pressure foot,so that the portion of the collection pad that is compressed by theouter pressure foot is dry at the time it is initially compressed. Theinitial dryness of the receiving, reaction pad is believed to enhancesignificantly the movement of liquid material from the collection padthrough the intervening filter to the reaction pad.

Having described the invention, what is claimed as new and secured byLetters Patent is:

1. A press for squeezing liquid material from an absorbent article, saidpress having a pressure assembly movable relative to a platen member forpressing the article therebetween, said press further comprising A. afirst foot member in said pressure assembly and having a firstarticle-pressing surface facing said platen member, said first footmember being movable with said pressure assembly to compressively engagesaid first surface against an article on said platen member with a firstforce,

B. a second foot member in said pressure assembly and having a secondarticle-pressing surface facing said platen member along a pathencircling said first surface, said second foot member being movablewith said pressure assembly and in the same direction as said first footmember to compressively engage said second surface against an article onsaid platen member with a second force different from said first force,and said second foot member compressively engaging said article prior tosaid first foot member upon movement of said pressure assembly towardsaid platen member, and said second foot member forming with said firstfoot member a liquid-tight seal between said first and second surfaces.

2. A press as defined in claim 1 A. in which one of said foot members isof elastically deformable resilient material and is movable directlywith said pressure assembly, and

B. further comprising resilient means coupled between said pressureassembly and the other foot member and resiliently urging said otherfoot member relative to said pressure assembly in the direction towardsaid platen member.

3. A press as defined in claim 1 A. in which said secondarticle-pressing surface encircles said first surface with a flat planarface and,

B. said first article-pressing surface has, in the absence ofcompressive engagement thereagainst, an outer peripheral portionbounding a central portion concavely recessed away from said platenmember relative to said peripheral portion.

4. A press for pressing liquid material from one porous article toanother layered therewith, said press having a frame with a platenmember thereon for receiving said articles and further comprising A. aplunger mounted on said frame for movement toward said platen member forcompressing said articles therebetween and alternatively movable awayfrom said platen member, said plunger having a resilient foot member onthe end thereof proximal to said platen member and which effects a firstcompressive engagement by said plunger against said articles,

B. a collar member slidably fitting over said plunger and receiving saidfoot member therein, said collar member having a first annular surfaceopposite a second annular surface that faces said platen memberconcentrically about said foot member and that effects a secondcompressive engagement against said articles, and

C. coil spring compression means compressed between said first annularsurface and said plunger and resiliently urging said collar slidablyalong said plunger in the direction toward said platen member, and

D. stop means limiting said movement of said collar along said plunger,said stop means normally maintaining said collar disposed with saidsecond annular surface spaced from said platen member by a distance notgreater than the spacing of said resilient foot member from said platenmember.

5. A press for squeezing liquid material from an absorbent article, saidpress having a pressure assembly movable relative to a platen member forpressing the article therebetween, said press further comprising A. ashaft included in said pressure assembly and axially movable relative tosaid platen member,

B. a first foot member in said pressure assembly carried on the end ofsaid shaft facing said platen member, and having a firstarticle-pressing surface facing said platen member, said first footmember being movable with said pressure assembly to compressively engagesaid first surface against an article on said platen member with a firstforce, and

C. a second foot member in said pressure assembly carried on said shaftand encircling said first foot member and having a secondarticle-pressing surface facing said platen member along a pathencircling said first surface,'said second foot member being movablewith said pressure assembly and in the same direction as said first footmember to compressively engage said second surface against an article onsaid platen member with a second force different from said first force,and said second foot member compressively engaging said article prior tosaid first foot member upon movement of said pressure assembly towardsaid platen member.

6. A press for squeezing liquid material from an absorbent article, saidpress having a pressure assembly movable relative to a platen member forpressing the article therebetween, said press further comprising A. aplunger included in said pressure assembly and axially movable relativeto said platen member with a first end facing toward said platen member,

B. a first foot member in said pressure assembly carried on said plungeras an axial extension thereof beyond said first end and of elasticallydeformable resilient material and having a first article-pressingsurface at the end thereof axially spaced from said plunger first endand facing said platen member, said first foot member being movable withsaid plunger to compressively engage said first surface against anarticle on said platen member with a first force, and

C. a second foot member in said pressure assembly and having a secondarticle-pressing surface facing said platen member along a pathencircling said first surface, said second foot member being movablewith said pressure assembly and in the same direction as said first footmember to compressively engage said second surface against an article onsaid platen member with a second force different from said first force,and said second foot member compressively engaging said article prior tosaid first foot member upon movement of said pressure assembly towardsaid platen member, said second foot member having a bore therethroughin which said resilient material of said first foot member is disposedand axially of which said plunger moves relative to said platen member,and normally having a toroidal spacing between the inner surface of saidbore and said resilient material of said first foot member and intowhich said latter element can deform upon compressive engagement betweensaid plunger and said article.

7. A press for squeezing liquid material from an absorbent article, saidpress having a pressure assembly movable relative to a platen member forpressing the article therebetween, said press further comprising A. Afirst foot member in said pressure assembly and having, a firstarticle-pressing surface facing said platen member, said first footmember being movable with said pressure assembly to compressively engagesaid first surface against an article on said platen member with a firstforce, and

B. a second foot member in said pressure assembly and having a secondarticle-pressing surface facing said platen member along a pathencircling said first surface, said second foot member being movablewith said pressure assembly and in the same direction as said first footmember to compressively engage said second surface against an article onsaid platen member with a second force greater than said first force,and said second foot member compressively engaging said article prior tosaid first-foot member upon movement of said pressure assembly towardsaid platen member.

8. A press for squeezing liquid material from a selected area of anabsorbent article and having a pressure assembly movable relative to aplaten member for pressing such an article therebetween, said pressfurther comprising pressure foot means A. having means forming anarticle-pressing surface facing said platen member,

B. mounted with said pressure assembly and movable therewith tocompressively engage said pressing surface against the article on saidplaten member,

C. having pressure-distributing means for engaging said pressing surfaceagainst the article, initially during such relative movement, along onlythe periphery of the selected area; and for subsequently, with continuedmovement, engaging said pressing surface against the article along pathswithin said periphery and of successively smaller path length and atleast maintaining previously effected engagement of said pressingsurface with the article, thereby to compress the selected area of thearticle progressively from the periphery thereof to the center, saidpressure-distributing means including l. a first foot member ofelastically deformable resilient material and movable with said pressureassembly for developing at least part of said compressive engagement ofsaid pressing surface with the article,

2. a collar-like member movable with said pressure assembly and in thesame direction as said first foot member and having at least a tubularportion encircling said first foot member, and

3. means normally forming a toroidal space encircling said first footmember inside said tubular portion of said collar-like member anddisposed to receive a radially outward bulge of said first foot memberupon said development of said compressive engagement.

9. A press for squeezing liquid material from an absorbent article, saidpress having a pressure assembly movable relative to a platen member forpressing the article therebetween, said press further comprising A. ashaft included in said pressure assembly and axially movable relative tosaid platenmember and having a first end facing said platen member,

B. a first foot member in said pressure assembly and including arod-like element of elastically deformable resilient material axiallyextending from said shaft beyond said first end thereof, said rod-likeelement having a first article-pressing surface facing said platenmember and being movable with said shaft to compressively engage saidfirst surface against an article on said platen member with a firstforce, and

C. a second foot member in said pressure assembly and having a secondarticle-pressing surface facing said platen member along a pathencircling said first surface, said second foot member being movablewith said shaft and in the same direction as said first foot member tocompressively engage said second surface against an article on saidplaten member with a second force different from said first force, andsaid second foot member compressively engaging said article prior tosaid first foot member upon movement of said pressure assembly towardsaid platen member, said second foot member including a collar carriedon said shaft adjacent said first end thereof and having at least aportion encircling said rod-like element of said first foot member.

10. A press as defined in claim 9 A. in which said collar is movableaxially of said shaft, and

B. further comprising resilient compression means compressively engagedbetween said collar and said shaft and resiliently urging said collaralong said shaft in the direction toward said platen member.

11. A press as defined in claim 10 further comprising a stop meanslimiting said movement of said collar relative to said shaft.

12. A press as defined in claim 9 including means normally toroidalforming a toroidal space encircling said rod-like element inside saidcollar and disposed to receive the radially-outward bulge of saidrod-like element upon compression thereof between said shaft and saidplaten-supported article.

13. In a press for squeezing liquid material from an absorbent articleand having a pressure assembly movable relative to a platen member forpressing the article therebetween, the combination in said pressureassembly comprising A. an axially extending collar member I. having atone axial end a second article-pressing surface facing said platenmember and having an axial passage therein open at said second surface,and

2. movable axially thereof between first and second positions with saidpressure assembly to be respectively withdrawn from said platen memberand to be proximal to said platen member for engaging said secondsurface against an article on said platen member,

B. a foot member 1. having a first article-pressing surface facing saidplaten member within said passage opening,

2. axially movable within said passage with said pressure assemblybetween a retracted position where said first surface is axiallyretracted within said passage from said platen member and said secondsurface, and a pressing position where said first surface is proximal tosaid second surface for compressive engagement against an article onsaid platen member, and

C. means forming a fluid-introducing aperture extending through the wallof said collar member in communication between the exterior thereof andsaid passage at a location between said retracted and said pressingpositions of said foot member within said passage.

14. In a press as defined in claim 13, the further combination A. inwhich said press assembly includes a shaft axially movable relative tosaid platen member, and

B. in which said foot member is carried on the end of said shaft facingsaid platen member.

A. in which said pressure assembly includes a shaft axially movablerelative to said platen member, B. in which said resilient means iscoupled between said shaft and said collar member, and

C. further comprising means coupling said foot member with said shaftfor movement of said foot member both toward and away from said platenmember relative to said collar member.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIONPATENT NO. 3 ,844, 717

DATED I October 29, 1974 INVENTOR(S) 1 Lester A0 Sodickson and FranklinLim It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below: Q

Column 3, line 56, the first word in the paragraph,

"the" should be --The---n Column 10, line 57, before "first footmember",

change "A" to --a--.

Column 12, line 24, cancel "toroidal" between 0 "normally" and"forming".

Signed and Sealed this twenty-eight Day of October 1975 [SEAL] Arrest:

. RUTH c. MASON c. MARSHALL DANN Arresting Officer Commissioner of Parents and Trademarks

1. A PRESS FOR SQUEEZING LIQUID MATERIAL FROM AN ABSORBENT ARTICLE, SAIDPRESS HAVING A PRESSURE ASSEMBLY MOVABLE RELATIVE TO A PLATENT MEMBERFOR PRESSING THE ARTICLE THEREBETWEEN, SAID PRESS FURTHER COMPRISING A.A FIRST FOOT MEMBER IS SAID PRESSURE ASSEMBLY AND HAVING A FIRSTARTICLE-PRESSING SURFACE FACING SAID PLATEN MEMBER, SAID FIRST FOOTMEMBER BEING MOVABLE WITH SAID PRESSURE ASSEMBLY TO COMPRESSIVELY ENGAGESAID FIRST SURFACE AGAINST AN ARTICLE ON SAID PLATEN MEMBER WITH A FIRSTFORCE B. A SECOND FOOT MEMBER IN SAID PRESSURE ASSEMBLY AND HAVING ASECOND ARTICLE-PRESSING SURFACE FACING SAID PLATEN MEMBER ALONG A PATHENCIRCLING SAID FIRST SURFACE, SAID SECOND FOOT MEMBER BEING MOVALBEWITH SAID PRESSURE ASSEMBLY AND IN THE SAME DIRECTION AS SAID FIRST FOOTMEMBER TO COMPRESSIVELY ENGAGE SAID SECOND SURFACE AGAINST AN ARTICLE ONSAID PLATEN MEMBER WITH A SECOND FORCE DIFFERENT FROM SAID FIRST FORCE,AND SAID SECOND FOOT MEMBER COMPRESSIVELY ENGAGING SAID ARTICLE PRIOR TOSAID FIRST FOOT MEMBER UPON MOVEMENT OF SAID PRESSURE ASSEMBLY TOWARDSAID PLATEN MEMBER, AND SAID SECOND FOOT MEMBER FORMING WITH SAID FIRSTFOOT MEMBER A LIQUID-TIGHT SEAL BETWEEN SAID FIRST AND SECOND SURFACES.2. axially movable within said passage with said pressure assemblybetween a retracted position where said first surface is axiallyretracted within said passage from said platen member and said secondsurface, and a pressing position where said first surface is proximal tosaid second surface for compressive engagement against an article onsaid platen member, and C. means forming a fluid-introducing apertureextending through the wall of said collar member in communicationbetween the exterior thereof and said passage at a location between saidretracted and said pressing positions of said foot member within saidpassage.
 2. movable axially thereof between first and second positionswith said pressure assembly to be respectively withdrawn from saidplaten member and to be proximal to said platen member for engaging saidseCond surface against an article on said platen member, B. a footmember
 2. A press as defined in claim 1 A. in which one of said footmembers is of elastically deformable resilient material and is movabledirectly with said pressure assembly, and B. further comprisingresilient means coupled between said pressure assembly and the otherfoot member and resiliently urging said other foot member relative tosaid pressure assembly in the direction toward said platen member.
 2. acollar-like member movable with said pressure assembly and in the samedirection as said first foot member and having at least a tubularportion encircling said first foot member, and
 3. means normally forminga toroidal space encircling said first foot member inside said tubularportion of said collar-like member and disposed to receive a radiallyoutward bulge of said first foot member upon said development of saidcompressive engagement.
 3. A press as defined in claim 1 A. in whichsaid second article-pressing surface encircles said first surface with aflat planar face and, B. said first article-pressing surface has, in theabsence of compressive engagement thereagainst, an outer peripheralportion bounding a central portion concavely recessed away from saidplaten member relative to said peripheral portion.
 4. A press forpressing liquid material from one porous article to another layeredtherewith, said press having a frame with a platen member thereon forreceiving said articles and further comprising A. a plunger mounted onsaid frame for movement toward said platen member for compressing saidarticles therebetween and alternatively movable away from said platenmember, said plunger having a resilient foot member on the end thereofproximal to said platen member and which effects a first compressiveengagement by said plunger against said articles, B. a collar memberslidably fitting over said plunger and receiving said foot membertherein, said collar member having a first annular surface opposite asecond annular surface that faces said platen member concentricallyabout said foot member and that effects a second compressive engagementagainst said articles, and C. coil spring compression means compressedbetween said first annular surface and said plunger and resilientlyurging said collar slidably along said plunger in the direction towardsaid platen member, and D. stop means limiting said movement of saidcollar along said plunger, said stop means normally maintaining saidcollar disposed with said second annular surface spaced from said platenmember by a distance not greater than the spacing of said resilient footmember from said platen member.
 5. A press for squeezing liquid materialfrom an absorbent article, said press having a pressure assembly movablerelative to a platen member for pressing the article therebetween, saidpress further comprising A. a shaft included in said pressure assemblyand axially movable relative to said platen member, B. a first footmember in said pressure assembly carried on the end of said shaft facingsaid platen member, and having a first article-pressing surface facingsaid platen member, said first foot member being movable with saidpressure assembly to compressively engage said first surface against anarticle on said platen member with a first force, and C. a second footmember in said pressure assembly carried on said shaft and encirclingsaid first foot member and having a second article-pressing surfacefacing said platen member along a path encircling said first surface,said second foot member being movable with said pressure assembly and inthe same dirEction as said first foot member to compressively engagesaid second surface against an article on said platen member with asecond force different from said first force, and said second footmember compressively engaging said article prior to said first footmember upon movement of said pressure assembly toward said platenmember.
 6. A press for squeezing liquid material from an absorbentarticle, said press having a pressure assembly movable relative to aplaten member for pressing the article therebetween, said press furthercomprising A. a plunger included in said pressure assembly and axiallymovable relative to said platen member with a first end facing towardsaid platen member, B. a first foot member in said pressure assemblycarried on said plunger as an axial extension thereof beyond said firstend and of elastically deformable resilient material and having a firstarticle-pressing surface at the end thereof axially spaced from saidplunger first end and facing said platen member, said first foot memberbeing movable with said plunger to compressively engage said firstsurface against an article on said platen member with a first force, andC. a second foot member in said pressure assembly and having a secondarticle-pressing surface facing said platen member along a pathencircling said first surface, said second foot member being movablewith said pressure assembly and in the same direction as said first footmember to compressively engage said second surface against an article onsaid platen member with a second force different from said first force,and said second foot member compressively engaging said article prior tosaid first foot member upon movement of said pressure assembly towardsaid platen member, said second foot member having a bore therethroughin which said resilient material of said first foot member is disposedand axially of which said plunger moves relative to said platen member,and normally having a toroidal spacing between the inner surface of saidbore and said resilient material of said first foot member and intowhich said latter element can deform upon compressive engagement betweensaid plunger and said article.
 7. A press for squeezing liquid materialfrom an absorbent article, said press having a pressure assembly movablerelative to a platen member for pressing the article therebetween, saidpress further comprising A. A first foot member in said pressureassembly and having a first article-pressing surface facing said platenmember, said first foot member being movable with said pressure assemblyto compressively engage said first surface against an article on saidplaten member with a first force, and B. a second foot member in saidpressure assembly and having a second article-pressing surface facingsaid platen member along a path encircling said first surface, saidsecond foot member being movable with said pressure assembly and in thesame direction as said first foot member to compressively engage saidsecond surface against an article on said platen member with a secondforce greater than said first force, and said second foot membercompressively engaging said article prior to said first foot member uponmovement of said pressure assembly toward said platen member.
 8. A pressfor squeezing liquid material from a selected area of an absorbentarticle and having a pressure assembly movable relative to a platenmember for pressing such an article therebetween, said press furthercomprising pressure foot means A. having means forming anarticle-pressing surface facing said platen member, B. mounted with saidpressure assembly and movable therewith to compressively engage saidpressing surface against the article on said platen member, C. havingpressure-distributing means for engaging said pressing surface againstthe article, initially during such relative movement, along only theperiphery of the selected area; and for subsequently, with continuedmovemEnt, engaging said pressing surface against the article along pathswithin said periphery and of successively smaller path length and atleast maintaining previously effected engagement of said pressingsurface with the article, thereby to compress the selected area of thearticle progressively from the periphery thereof to the center, saidpressure-distributing means including
 9. A press for squeezing liquidmaterial from an absorbent article, said press having a pressureassembly movable relative to a platen member for pressing the articletherebetween, said press further comprising A. a shaft included in saidpressure assembly and axially movable relative to said platen member andhaving a first end facing said platen member, B. a first foot member insaid pressure assembly and including a rod-like element of elasticallydeformable resilient material axially extending from said shaft beyondsaid first end thereof, said rod-like element having a firstarticle-pressing surface facing said platen member and being movablewith said shaft to compressively engage said first surface against anarticle on said platen member with a first force, and C. a second footmember in said pressure assembly and having a second article-pressingsurface facing said platen member along a path encircling said firstsurface, said second foot member being movable with said shaft and inthe same direction as said first foot member to compressively engagesaid second surface against an article on said platen member with asecond force different from said first force, and said second footmember compressively engaging said article prior to said first footmember upon movement of said pressure assembly toward said platenmember, said second foot member including a collar carried on said shaftadjacent said first end thereof and having at least a portion encirclingsaid rod-like element of said first foot member.
 10. A press as definedin claim 9 A. in which said collar is movable axially of said shaft, andB. further comprising resilient compression means compressively engagedbetween said collar and said shaft and resiliently urging said collaralong said shaft in the direction toward said platen member.
 11. A pressas defined in claim 10 further comprising a stop means limiting saidmovement of said collar relative to said shaft.
 12. A press as definedin claim 9 including means normally toroidal forming a toroidal spaceencircling said rod-like element inside said collar and disposed toreceive the radially-outward bulge of said rod-like element uponcompression thereof between said shaft and said platen-supportedarticle.
 13. In a press for squeezing liquid material from an absorbentarticle and having a pressure assembly movable relative to a platenmember for pressing the article therebetween, the combination in saidpressure assembly comprising A. an axially extending collar member 14.In a press as defined in claim 13, the further combination A. in whichsaid press assembly includes a shaft axially movable relative to saidplaten member, and B. in which said foot member is carried on the end ofsaid shaft facing said platen member.
 15. In a press according to claim14, the further combination in which said collar member encircles saidfoot member and the end of said shaft on which it is carried.
 16. In apress according to claim 13, the further combination of resilient meansresiliently urging said collar member toward said platen member relativeto said foot member.
 17. In a press as defined in claim 16, the furthercombination A. in which said pressure assembly includes a shaft axiallymovable relative to said platen member, B. in which said resilient meansis coupled between said shaft and said collar member, and C. furthercomprising means coupling said foot member with said shaft for movementof said foot member both toward and away from said platen memberrelative to said collar member.